Flow restrictor



Oct. 22, 1957 o. u JR I 2,810,607

FLOW RESTRICTOR Filed May 31, 1955 JOHN D. HRUBY, JR

HUEBNER,BEEHL ER,

WORREL & HEPZIG,

ATTORNE Y5- INVENTOR.

FLOW RESTRICTOR John 0. Hruby, Jr., Burbank, Califi, assignor to Rain Jet Corp., Los Angeles, Calif., a corporation Application May 31, 1955, Serial No. 512,129

7 Claims. (Cl. 29960) This invention relates to restrictors for controlling the flow of fluids through conduits.

While the invention may be employed advantageously for various conduit installations, including, for example, heating systems and overhead sprinkler systems, I have chosen to illustrate and describe the invention as the same may be embodied in a lawn sprinkler system, for when so described, the advantages of the invention become readily apparent.

In conventional lawn sprinkler systems, a pipe leading from a water line is laid in the ground and a plurality of short risers are connected to it for attaching sprinkler heads to the pipe. In some installations several sprinkler heads are connected to a single pipe in a series arrangement, and in other installations several pipes are employed, each of which may include a plurality of sprinklers in series arrangement. In the case of several sprinklers arranged in series, an upstream sprinkler will receive water at a higher pressure than a sprinkler located downstream thereof, and thus the spray of water from the upstream sprinkler will be greater than that from a downstream sprinkler. Also, where difierent lengths of pipe are employed to connect sprinklers at different distances from a common water line, the water pressure in a sprinkler farthest away from the water line will be less than that in a sprinkler positioned nearer the water line. Then, too, the water pressure in a sprinkler positioned at a given level will be greater than the pressure of water in a sprinkler of the same system but positioned at a higher level.

For at least partially equalizing the pressure of several sprinklers in a given installation, one may employ pipes of different diameters, i. e. a sprinkler proximate the main water line may be connected into the system with a riser of small diameter, while a sprinkler further removed from the water line is connected by a riser of larger diameter. As the various sizes of standard pipes are limited, this method of equalizing pressures in a single system is not entirely satisfactory and is relatively expensive to install, for it requires the use of pipe fittings of various sizes and an expert knowledge of water pressures and how pressures may be controlled by utilizing pipes of given diameters. Furthermore, accurate adjustment is not attainable from the use of pipes of standard sizes.

An object of this invention is to provide an improved method and means for equalizing flow of fluid from a plurality of outlets in a system.

The sprinkler systems of the type herein illustrated are designed for installation on a do-it-yourself basis, i. e. installation may be made simply and reliably even by home owners who are not skilled in the pipe fitting art, and accordingly it is an object of this invention to provide a means for equalizing the pressure water from spaced apart sprinkler heads in a sprinkler system which is simple to install and adjust for uniform distribution of water, no matter what the pipe arrangement of the sprinkler system may be.

State .l. atent ice A further object of the invention is to provide an improved restrictor for a pipe which is simple in construction and may be manufactured on a mass production basis for the purpose of supplying the public with restrictors at low cost.

Further objects and advantages of the invention will appear in the following part of this specification, wherein the details of construction and mode of operation of a preferred embodiment of the invention are described with reference to the accompanying drawing, in which:

Fig. l is a representation of a portion of a pipe in a lawn sprinkler system, the pipe having a plurality of risers connected thereto for mounting sprinkler heads;

Fig. 2 is a side elevation of a riser and a portion of the water pipe to which it is connected, and a sprinkler head mounted thereon, the riser and pipe being shown partially in central vertical section to expose a flow restrictor embodying the invention;

Fig. 3 is a central vertical section through the restrictor; and

Fig. 4 is a perspective view of the restrictor, before being mounted in a system.

Referring to the drawing in greater detail, and with,

the use of reference numerals, a water conduit or pipe for supplying water to several sprinklers in a lawn sprinkler system is shown and designated generally by reference numeral 10. The pipe 10 is made up of a plurality of pipe sections 11 which are threadably connected end to end with pipe Ts 12. One end 13 of the pipe 10, herein referred to as the upstream end, is adapted to be connected to a valve controlled water line (not shown) by which water is admitted to the pipe. The other end of the pipe 10 terminates in an elbow 14 by which the sprinkler furthest removed from the water line is connected to the pipe. The elbow 14 is herein referred to as the downstream end of the pipe 10. The pipe sections are of uniform size. The horizontal flow passage in the pipe T 12 appearing in Fig. 2 is designated by numeral 15, while the vertically extending passage thereof is designated by numeral 16.

Each of the upwardly extending legs of the elbow 14 and the upwardly extending leg of each pipe T threadably receive a pipe nipple or riser. These risers are designated by numerals 18, 19, 20 and 21, respectively, the riser 21 being fitted into the elbow 14., In the illustrated embodiment the risers are of equal length so that the pipe 10 may be laid at a uniform depth in the lawn. The vertical passage through the riser 18 is designated by numeral 22.

To complete the installation of a lawn sprinkler systern, sprinkler heads of any desired type are connected to the top end of each riser. The drawing shows a sprinkler head 24 connected to the top end of riser 18, which head is of the general type illustrated and described in my Patent No. 2,639,191, issued May 19, 1953.

As thus far described, it will be apparent that the pressure of water in the upstream riser 18 will be greater than that in any of the risers located downstream thereof, and should water under pressure he admitted to the pipe 10 before sprinkler heads are mounted on the several risers, it will be seen that the stream of water from the riser 18 will be higher than that from the remaining risers which in turn produce streams of less height as the downstream end 14 of the pipe 10 is approached. Such decrease in water pressure will result in a smaller area of water distribution from the most downstream sprinkler than from any sprinklers located upstream thereof.

This invention makes it possible to simply and effectively equalize the pressure or flow of .water from each of the several risers in a sprinkler system. This is accomplished by positioning a restrictor, embodying the invention, in each riser and then adjusting the opening of each ing of said other end into an elongate opening of an area which is less than the cross sectional area of that portion of the tube passage positioned between the planes of said annular end faces, the tube having a transverse dimension in that portion thereof adjacent said other end which is greater than the diameter of said bore, thereby preventing the tube from sliding out from the bore in a direction opposite to said one direction.

5 A conduit having an internal passage extending therethrough defining an upstream opening at one end of the passage and a downstream opening at the opposite end of the passage, a flow restrictor secured in the passage, said restrictor comprising an open-ended tube of malleable material spaced from the walls defining the conduit passage, a collar fixed around the tube and spanning the space between the tube and the walls defining the conduit passage, said tube having one end thereof directed toward the downstream opening in the conduit and extending beyond the collar, said tube having opposite portions of the walls thereof adjacent said one end of the tube bent toward each other to define a tube opening which is smaller in area than the inside cross sectional area of any other part of the tube.

6. A lawn sprinkler system comprising a conduit having an internal passage therein, one end of the conduit being a downstream end and the other end being an upstream end adapted to be connected to a water supply line, said passage being closed in the downstream end thereof, a plurality of open-ended tubular risers extending upwardly and being connected at spaced apart points to the conduit for flow of water from the conduit passage up through the risers, a plurality of sprinkler heads connected respectively to the upper ends of the risers, each riser having a flow restrictor releasably secured therein, each restrictor comprising an open-ended tube extending longitudinally in its respective riser whereby one end of the tube is a lower end and the other tube end is an upper end, said tube being spaced from the inside walls of its respective riser, a collar fixed around the tube and spanning the space between the tube and the said inside walls of its respective riser, the lower end of the tube defining a tube opening which is smaller in area than the internal cross sectional area of any other portion of the tube, and the lower end tube openings of the plurality of restrictors in the system being successively of greater area from the upstream end of the conduit to the downstream end thereof.

7. A lawn sprinkler system according to claim 6 in which said tubes extend downwardly from their respective collars and substantially to the cylindrical surface defining the conduit passage.

References Cited in the file of this patent UNITED STATES PATENTS 577,362 Ettlinger Feb. 16, 1897 1,527,222 Rasmussen Feb. 24, 1925 1,889,201 Holveck Nov. 29, 1932 2,563,300 Aker Aug. 7, 1951 2,598,961 Andrus June 3, 1952 2,639,191 Hruby May 19, 1953 2,697,582 Grosch Dec. 21, 1954 2,709,623 Glynn May 31, 1955 FOREIGN PATENTS 12,086 Great Britain May 19, 1911 

